The Canon 300 L f/4 is becoming one of my favorite lenses to use at weddings and even for portrait head shots. Many photographers prefer the 70-200mm but I find that I use this much more often than my 70-200. The photos are very sharp and I can get in real close and not disturb a wedding ceremony. The image stabalization really help when I have to use slower shutter speeds. I can take photos that look more natural and less staged with this lens. Even my 135L F2.0 is not being used as much!